1. Field of the Invention
The present invention relates to the structure of thin film transistor liquid crystal display (TFT-LCD), and in particular to a LED backlight module and the corresponding liquid crystal display.
2. The Related Arts
Among the existing technology, light emitting diode (LED) is commonly used as the light source of TFT-LCD backlight because it has the advantage of high energy efficiency.
The schematic view illustrating the structure of the backlight module according to the prior art is shown in FIG. 1. The backlight module comprises: a backplane 10, a PCB plate 20 provided on the backplane 10, and a reflective plate 30. Wherein, multiple bottom lighting sources 40, which are as LED, are provided on the reflective plate 30, which is electrically connected to the reflective plate 30 through the PCB plate 20. The light emitted from bottom lighting source 40 is facing the optical film set 70.
In pace with the future development of the energy saving concept, the current TFT-LCD backlighting requires further energy saving. It is necessary to reduce the number of LEDs to achieve the reduction of power consumption. Nowadays, second lens technology is adopted to change the LED light pattern, thereby reducing the light mixing distance of the LED and also the number of LED usage. However, there is a bottleneck to further reduce the energy consumption.
With the progression of the technology, the light efficiency of LED is increasing. Moreover, the increase of the power of LED causes the increase of the flux enhancement of LED. The flux of single LED is very high when high power LED is used. Hence, under the same module specification, the number of LED usage can be reduced. However, in the bottom lighting LED backlight module structure, because the light intensity right above the LED is larger, and the light intensity within the LEDs is smaller, the chromatic aberration of LED (Mura) is more obvious.
However, in the structure of the side-type backlight module, it would produce significant hot spots when the number of LEDs is reduce because the light mixing distance between the LED and the light guide plate is limited. In order to solve such problems, the light mixing distance between the LED and the light guide plate is usually increased, which conflicts with the narrow frame of the liquid crystal display panel.